Some biological characteristics of a pituitary growth factor (CGF) for cultured lapine articular chondrocytes
✍ Scribed by Charles J. Malemud; Leon Sokoloff
- Publisher
- John Wiley and Sons
- Year
- 1974
- Tongue
- English
- Weight
- 683 KB
- Volume
- 84
- Category
- Article
- ISSN
- 0021-9541
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✦ Synopsis
Abstract
A recently described pituitary chondrocyte growth factor (CGF) is a contaminant of several related glycoprotein hormones (TSH, LH and HCG). Chondrocytes were cultured from rabbits two to three months old. Bovine TSH (NIH) 69.5 μg/ml, used as the source of CGF, reduced the generation time from 16 to 10 hours through a virtual effacement of the G~1~ period. Incorporation of ^3^H‐thymidine declined rapidly after 48 hours from maximal values (control 300 cpm/μg DNA; CGF, 679). Total DNA accumulated thereafter until 116 hours when the figures were 36 and 98 μg/flask, respectively. Little growth response occurred in spinner cultures. CGF lowered plating efficiency from 4.5 to 2.3%. The stimulatory effect diminished when CGF was removed from the medium. The treated cells were smaller and contained less protein and RNA than controls. They synthesized smaller quantitites of sulfated mucopolysaccharides (chondroitin sulfates 4,6 and doubly sulfated chondroitin as well as some dermatan sulfate) but hyaluronate production was not diminished.